I'm glad people were able to get something out of this. Sure Portra 400 and 400H would have been interesting, but I didn't have a back with Portra 400 in it, too bad.
My experiment was to see how these films compared and handled overcast weather, not to mention if shooting at ISO 50 would be do-able hand held with a medium format camera in the typical overcast skies we have here in Portland.
Personally I think the Ektar looks 100x better in this situation. The 400H although having a more even, neutral tone is flat and dull. I just bought a pro-pack to do more experiments with it. I've got some work coming up that I might shoot on Ektar instead of 400h..
As far as shooting/dev info this is all I know:
Mamiya 645AFD w/ 80mm f/2.8 @f/2.8
Ektar 100 @ ISO 50
400H @ ISO 200
Developed/Scanned at RPL using their typical dip-n-dunk and scanned on their Noristu.